1. Field of the Invention
This invention relates to an apparatus and method for distributing concurrent incoming calls on a plurality of lines to a plurality of resources.
2. Description of the Related Art
For a number of customer services, incoming telephone calls need to be distributed to a finite number of resources and difficulties have arisen hitherto in prioritizing the calls for connection to the resources. For example, in a telephone directory assistance service, incoming calls need to be connected to a fixed number of resources in the form of manual telephone operators. A number of approaches have been adopted previously to optimize the connection of incoming calls so as to minimize queuing. Reference is directed to "The Edgeley Electronic Queuing Equipment" D. R. Donnelly and R. J Hirst, British Telecommunications Engineering, Vol. 1, part 3, October 1982, p 155. More sophisticated systems have been proposed, to include multiple queues, priority lines, alternative routings and calendar time of day routing plans. The previous approaches have all used rules-based algorithms in order to meet customers requirements. However, as the number of incoming lines and resources is increased, the rules required for the algorithm become very complex and difficult to optimize in themselves. An example of a rules based procedure is set out in FIG. 1 and comprises a series of IF statements IF1, IF2, etc. Each IF statement is designed to provide a specific test for incoming calls. The chevrons &lt; &gt; indicate customer specified tests or values to enable individual customers to be connected depending on their priority or their particular needs. Different priorities may be given to different telephone numbers, for example.
While a call is waiting, the IF statements are read from the top down repetitively until one of the IF statements becomes true, and then the action specified in the statement is carried out.
However, it will be seen that this configuration becomes unwieldily and unduly complicated when a large number of incoming calls are to be processed and connected to a large number of resources. The rules based system shown in FIG. 1 permits calls to be allocated to different queues. The resources answering the calls may support more than one queue i.e. be able to deal with enquiries of more than one type, so that balancing the incoming call load to the individual resources becomes a complex problem usually requiring manual intervention by a network supervisor. The present invention provides an alternative approach which seeks to overcome the restrictions associated with the prior rules-based systems.